302 NORTH AMERICAN INSECTS. 



where the sun shines brightly. The female is larger than 

 the male ; and when about ready to lay her eggs, the hind 

 body becomes so transparent that the eggs are seen through 

 it on both sides. The development of the egg may best be 

 observed by putting moistened wheat or barley into a glass 

 vessel, and leaving it until it is spoiled and has become 

 black, when three or four eggs will be seen on the grains 

 and may be closely watched. These eggs are cylindrical in 

 form, pointed at one end, and its surface shines like mother- 

 of-pearl. After about twenty-four hours the maggot leaves 

 the egg, and grows for two weeks, until it is about three 

 lines long, when it is metamorphosed into a cylindrical red- 

 brown pupa, from which the perfect fly, with its hairy gray 

 feet, issues in about two weeks. These hairy feet arc of 

 great use to this little insect, and assist in keeping it nice 

 and clean, because it uses them as brushes, with the hind 

 ones to brush the dust from its wings, and with the fore 

 feet wiping its face and eyes. 



As these flies torment man, they are in the same ratio 

 themselves tormented by very small mites, which in large 

 numbers move between their hairs, and which they can not 

 get rid of by any means. We resort to many measures to 

 abate the nuisance of flies, and there are many mixtures 

 recommended as sure death to these our little tormentors ; 

 but it is doubtful, with all of them, whether they do not at- 

 tract the flies in greater proportion than they destroy them. 

 Dr. Harris says: "If a plateful of strong green tea, well 

 sweetened, be placed in an outer apartment, accessible to 

 flies, they will taste of it, and be killed thereby as soon as 

 by the most approved fly-poison." 



The MEAT-FLY (Musca vomitoria) is about half an inch 

 long, and two lines thick, hairy, black, and has a shining 

 blue hind body. This insect is remarkable for its extraor- 

 dinary sense of smell, and hence a piece of meat can hardly 

 be placed out of its reach ; for, unless very securely closed 



